The present invention generally relates to an improved dynamic assignment protocol for a radio network, more particularly relates to a protocol for full-duplex communication, and even more particularly relates to an extension to USAP for enabling full-duplex communication.
Mobile multi-hop packet radio networks are known for rapid and convenient deployment, self-organization, mobility, and survivability. Many applications require self-organizing, wireless networks that can operate in dynamic environments and provide peer-to-peer, multi-hop, multi-media communications. Key to this technology is the ability of neighboring nodes to transmit without interference. Neighboring nodes transmit without interference by choosing time slots and channels that do not cause collisions at the intended unicast or multicast receivers.
Receivers are generally capable of processing only one transmission at a time. When using such receivers, simultaneous transmissions (also known as collisions, contentions or conflicts) can be avoided by assigning a specific transmission time slot to each communicating node. Several approaches have been developed for assigning communication slots to nodes. The approach chosen for a particular application is generally related to the type of network application (broadcast, multicast, unicast, datagrams, virtual circuits, etc.) being implemented.
The Unifying Slot Assignment Protocol (USAP), which is disclosed in U.S. Pat. No. 5,719,868, provides a protocol establishing one such contention avoidance system. USAP is a dynamic assignment protocol that monitors the RF environment and allocates channel resources on demand. It automatically detects and resolves contention between nodes for time slots, such contention arising for example from changes in connectivity. U.S. Pat. No. 5,719,868, issued Feb. 17, 1998, is hereby incorporated herein by reference in its entirety, including all drawings and appendices.
USAP permits a node to assign itself transmit slots based on information it has regarding when it is assigned to transmit and receive and when a neighboring node is scheduled to transmit. The original USAP embodiments were designed for use with half-duplex radios and therefore do not support full-duplex communication. Since a full-duplex radio can transmit and receive at the same time, the use of full-duplex radios presents the potential of doubling network throughput relative to half-duplex radios. As a result, there exists a need for a dynamic assignment protocol that can support full-duplex radios. This need is addressed and fulfilled by the detailed description provided below.
It is an object of the present invention to provide an improved dynamic assignment protocol.
It is a feature of the present invention to utilize an assignment formula particularly suited to the support of full-duplex radios.
It is an advantage of the present invention to enable a dynamic assignment protocol such as USAP to be used in a network containing full-duplex radios.
The present invention provides an improved dynamic assignment protocol suitable for use with full-duplex radios. It is carried out in a xe2x80x9ccontention-lessxe2x80x9d manner such that collisions between communications transmitted between full-duplex radios are avoided. The invention includes embodiments for determining unicast and broadcast communication slot allocations.